Singaporean Prime Minister Lee Hsien Loong has lauded RCEP, saying it will create opportunities for businesses. He also says the agreement will further increase trade between ASEAN and China.

At its core, RCEP is a proposed free-trade agreement made up of the 10 ASEAN countries. Signatories that joined later are split up into two groups: ASEAN+3 and ASEAN+6. China, Japan, and South Korea make up ASEAN+3, while India, Australia, and New Zealand are added to form the ASEAN+6. 

Altogether, RCEP consists of 16 countries, accounting for more than three billion people or almost half of the world's population. It covers a combined total GDP of 21.3 trillion US dollars, or 40 percent of world trade.

RCEP was first introduced at the 19th ASEAN Summit in November 2011. The next year, ASEAN leaders agreed to the framework for RCEP. Negotiations began in May 2015 and have been ongoing since. The meetings in Singapore are expected to lead to the broad outlines of a deal.

RCEP's combined GDP surpasses the Trans-Pacific Partnership agreement - another proposed free trade deal. GDP and trade volume among RCEP nations last year was almost double that of the 11 nations in the TPP talks. The most notable feature is that the combined total population that would fall under RCEP is more than seven times that of TPP countries, showing just how big the impact this free trade deal could have on the world.